You are reading the quote incorrectly. The Pope is mocking Communists. He says that Christians started helping people "twenty centuries" ago but Communists only started helping people recently. He's saying that Christians own the concept of helping people and when Communists help other people, it is because they are copying Christians. He's saying this in jest, I hope. It is banter but still he's mocking communists. He's not saying this to support Communists.